Supporting and level control mechanism for concrete slab laying machines



Dec. 16, 1958 R. M. GUNTERT ETAL 2,864,452

SUPPORTING AND LEVEL CONTROL MECHANISM FOR CONCRETE SLAB LAYING MACHINES Filed Nov. 5, 1956 5 Sheets-Sheet 1 H TTYS.

De- 16, 1958 R. M. GUNTERT ETAL 2,864,452

SUPPORTING AND LEVEL CONTROL MECHANISM FOR CONCRETE SLAB LAYING MACHINES Filed NOV. 5, 1956 5 SheetS-Sheet 2 IN VEN TORS RM Garnier? Decl5, 1958 R. M. GUNTERT ETAL 2,864,452

SUPPORTING AND LEVEL CONTROL MECHANISM FOR CONCRETE SLAB LAYING MACHINES Filed Nov. 5, 1956 5 Sheets-Sheet 3 IMJ HTTYS.

Dec. 16, 1958 R. M. GUNTERT ET AL 2,864,452

SUPPORTING AND LEVEL CONTROL MECHANISM FOR CONCRETE SLAB LAYING MACHINES 5 Sheets-Sheet 4 Filed Nov. 5, 1956 SH R U/ G C maar m m m mm www h l W hm wd..

Dec- 16, 1958 R. M. GUNTERT HAL 2,864,452

SUPPORTING AND LEVEL CONTROL MECHANISM FOR CONCRETE SLAB LAYING MACHINES Filed Nov. 5, 1956 5 Sheets-Sheet 5 IN VEN TORS QQ \H ,eM @um W Nm BY @figer/@y fu-,2L 'ra/zal;

United States PatentO SUPPORTING AND LEVEL CONTRL MECHA- NISM FOR CONCTE SLAB LAYING MA- CHINES Ronald M. Gunter-t and Wilbur F. Barley, Stockton, Calif., assignors to Guntert & Zimmerman Const.

Div., Inc., Stockton, Calif., a corporation of California Application November 5, 1956, Serial No. 620,498 '7 Claims. (Cl. M50-9.1)

.the machine on self-propelled endless track units which directly engagethe ground to the sides of the area ofthe strip to rbe poured, rand to provide automatically functioning means to maintain the machine at a constantand 1 accurate level irrespective r irregularities in engagedby the endless track units. y

yIn connection with the mounting ofthe endless track units, a further object of the invention is to so connect said units to the machine that either unit may be'so connected at a higher or lower working level than the other unit, as operational conditions may necessitate, and withoutr affecting the operation of the automatic Vleveling means.

Such leveling means includes a taut wire pre-set to gradealongside the path to be traversedlby the machine during the concretelaying operation, just as in the structure of the aforementioned pending application; and a further, object of this invention is to provide animproved the ground and more practicabletypeof feeler unit, including a probe element engageable with sadwire, than was previously the case. f

The endlesstrack units are arranged to .be separately self-propelled at the same speed, and another object of this `.invention is to `provide automatically functioning means, actuated by one of the grade wires, to cause the machine to be steered as it advances, by discontinuing thel drive'of one trackunit orthe other.

Still another object of theinvention is to provide y,a practical, reliable, and durable control mechanism for concrete slab laying machines, and one which Willy be exceedingly eifectivev for the purpose for which it is designed. f

These Iobjects are accomplished by means of such structure andrelative arrangement of parts as will fully appear by a perusal of the following specification and claims.

`In the drawings:

Fig. l vis aside elevation of the assembly, partly broken away.

Fig. 2 is a Ysomewhat enlarged andiforeshortened front endelevation of the structure, partly broken away and in section.

' Fig. 3 is a fragmentaryenlarged plan View of one of the .track .and bolster units, showing the corresponding gradecontrolvunits andthe steering control unit thereon and in cooperating relation with the adjacent combination grade and horizontal alinement control wire.'

Fig. 4 is an enlarged rear end elevation, `partly broken away and in section, of one of the wire-engaging movement control units, detached.

Fig. S'is'a sectionalplan on line 5-5 of Fig. 4.

c Fig. 6`is a fragmentary longitudinal section taken on line 6-46 of Fig. 4. f

Fig. 7 is a diagram, mainly in plan, of theV machine showing the grade-,wire controlled .steering-circuit arrangement, and one of the grade-wirecon'trolled ram-actuatingunits. I

Referring now more .particularly tothe drawings, and to the characters of reference marked thereon, the assembly comprises identical transversely/spaced vendless `track units 1, which support-and between which-#the concrete laying or paving structure is located. It maybe here stated .that this structure, indicated generally Vat 2, forms of itself lno part ofthis invention. `It suffices to saythat said structure includes a transversely extending distributing hopper 3 from which the concrete isy deposited on the roadbed in the form of a strip 4, the thickness of which is determined by asmoothing pan 5 mounted directly behind the hopper, and whose width is determined bysideskirtst. Y f

Extending lengthwise of a'nd directly above each track unit 1 is a relatively short `rigid` bolster?, such bolsterand vtrack unit together forming a supporting truck for the machine. At its front end the bolster is secured to a ver- .tical hydrauliccylinderor ram y8, while a similar cylinder or ram 9 at the rear end of the bolster is connected thereto by means of ktransverse vtrunnions 10. The depending plungers 11 of these cylinders are rigidly connectedto yokes 12 which straddle the track unit 1, and at their lower end are connected by transverse pivots 13 to the main longitudinal frame ,14 of unit 1.

-In order that the track unit lmay swing downwardly relative to the bolster about the pivot 13 of the front ram as an axis, and without then inducing a tendency to create vacuum in the rear ram 9, suitable means is pro.- vided to allow ofdownward movement of the rear 'ram asa whole relative to the bolster. Such means is here shown as being a slide ring 10a embracingthe ram cylinder on which ring the trunnions 10 are secured. The load is normally .taken byva shoulder 9a fixed on said ram cylinder and on which the ring rests.

A rigid fender 1S extends over the upper run 16 of the track of unit 1 for substantially the full lengthv thereof, andis supported from frame 14. vA driving unit for .the track is mounted on the rear end portion of the fender, behind the bolster; said unit comprising an electric motor 17, a change-.speed transmission 18 driven from the motor, a reduction gear unit 19 drivenfrom the transmission, and chain drives Ztlconriecting the output shaft 21 of the gear unit on both sides ofthe track (see Fig. 7) and the transverse drive shaft 2210i the track. i

Current for the drive motors of both track units 1 .is obtained from an engine-driven generator 23 (see Fig. 7) mounted on a platform 24 supported by lateral beams 25 projecting out from and rigid with one of the bolsters 7.

Each bolster 7, Ilaterallyin a short distance, is provided with rigid vertical longitudinally spaced plates l26 which abut against, and are vertically slidable relative to, corresponding but elongated plates 27v which are yrigid with uprights 28. f

kThe uprights in turn are rigid with cross beams 29, which-together with uprights AZ8-form a rigid frame. on which the paving structure 2 is mounted, yso that said structure and the uprights together form a rigidy unit.

Plates 26 and 27 are clamped together by removable bolts 30; plates 27 being provided with rows of bolt holes 31 positioned to match with those in plates' 26 with different positions of said latter plates relative to plates 27.

In order to automatically raise or lower either track unit at either or both ends relative to the paving machine so that the latter is maintained at a constant level regardless of undulations in the ground over which the track units may pass, and also to automatically steer the track units, and thus the assembly as a whole, the following control arrangement is provided:

Setaccurately to grade on both sides of and laterally out from the assembly are grade wire 32, positioned-on the average-a foot or so above the ground surface engaged by the track units. These wires are also set to be parallel to the horizontal path which it is desired the paving shall follow.

Depending from the outer face of each bolster 7 adjacent its ends, and so as to be clear of the track unit below, are arms 33 detachably bolted to the bolster, as at 34, for vertical adjustment relative thereto.

' Secured on the lower end of each arm is a feeler unit F. This unit comprises a rearwardly facing U-shaped.

bracket35, between the opposed end anges of which a turnable hand-controlled screw shaft 36 extends; said `flanges being provided with bosses 37 in which the shaft is journaled.

A block 38 is threaded on the shaft, which block is yieldably held against rotation on said shaft by means of a spring-pressed roller 39 mounted for sliding movement axially of the shaft 36 in a boss 40 rigid with the block 38, and engaging a vertically elongated track plate 41, which is curved horizontally and eccentric to shaft 36 in such a manner that the roller 39 becomes increasingly loaded as the unit swings to one side or the other from a neutral position. The eccentricity of the plate relative to the shaft 36 is such that the spring-urged roller 39 will always return to a central position after pressure acting to rotate the block is relieved.

A horizontal shank 42 is slidable through the block in front of the shaft 36; said shank being held in any desired position relative to the block by means of a hand clamping screw 43. In order that the shank 42, which is preferably made of round stock, will not turn in the block 38, said shank is flattened, as shown at 42a, where engaged by the clamping screw 43. The shank at its outer end is rigidly secured to a housing 44. A probe in the form of an elongated finger 45, positioned in longitudinal alinement with the shank, is pivoted intermediate its ends in the housing, as at 46, on an axis parallel to the grade wire; the portion of the nger outwardly of the housing being longitudinally horizontally slotted from its outer end, as at 47, so as to form a prong to receive the grade wire in free running relation.

The grade wires 32 are supported at intervals by brackets B projecting from stakes S, and the yieldable swinging mounting of the feeler unit on shaft 36, as previously described, enables the probe finger 45 to yield and move past the various brackets B in turn. In order to prevent actual contact of the probe nger with any bracket, a rigid guard or strike plate 45a is mounted on the housing 44 and projects in front of the nger for the length thereof and adjacent the same. 'I'his striker is formed with a longitudinal slot, as shown at 47a, this slot being considerably Wider than slot 47 so as not to contact the wire 32 with any ordinary vertical movements of the feeler unit relative to said wire. The striker will thus engage the bracket B upon advance of the machine and cause the feeler unit to swing clear of the bracket without possible damage being done to the iinger 45.

Mounted in the housing back of the pivot 46 on opposite sides of-or above and below-the probe nger, are sensitive limit switches 48 of conventional design, and each of which includes a press button 49 which engages the adjacent Aface of the Enger even when said finger is in a neutral position and the switch is open.

Stops are xed in the housing beyond the switches for engagement with, but normally clear of, the probe linger so as to limit the swinging movement of said ringer and prevent possible damage being done to the switches by such movement. The housing end of the shank 42 is drilled for some distance to provide a passage 51, open to the periphery of the shank back of the housing shown in Fig. 4, for the wiring (not shown in said figure) leading from the switches to the apparatus which controls the feeding to, or discharge of uid from, the corresponding hydraulic cylinder or ram.

Such apparatus, and the necessary circuits therefor, are shown in Fig. 7 for one feeler unit and ram only, since identical apparatus, except for the pump 52 and return or supply tank 53, is required for each feeler unit and ram. Hence, a description of one such apparatus will obviously suice for all.

Interposed between the pump and a ram 8, for instance, is a valve 54, preferably of a standard plunger or piston type and including a reciprocating valve member 55. A feed and return conduit 56 is connected to the casing of the valve and to the ram at the head end thereof, while other conduits 57 and 58 connect the valve casing and the pump 52 and tank 53, respectively.

The conduits are arranged so that upon movement of the valve member in one direction or the other from a neutral position, fluid is fed from the pump to the ram, or released from the ram and returned to tank 53. Such movement is imparted to member 55 by op posed, alternately functioning solenoids 59 and 59a, respectively, operatively acting on the axial stem 60 of the valve member, and whose circuits 61 and 62 are connected to a source of current, such as the generator 23.

Normally open relay switches 62 and 62a are interposed in the circuits 61 and 61a; the normally deenergized actuating coil 63 of each such switch being interposed in a circuit 64 in which one of the switches 48 of the corresponding feeler unit F is interposed.

The circuits of the relay switches are arranged relative to the feeler actuated switches so that when the probe 45 of the corresponding feeler unit swings down for instance, as when the bolster and track unit at the corresponding end and side of the machine are lowered and the lower switch 48 is closed, the solenoid 59a will be energized. This will shift the valve member to a position such that fluid will be fed to ram 8 and cause the bolsterand the paving structure` connected thereto-to be raised relative to the track unit.

Since there is a feeler unit, and a ram controlled thereby, adjacent each corner of the machine, the level of the machine will be accurately maintained as it moves along, without any attention on the part of the operator being necessary.

It may be desired to operate the various valves 54 by hand at times, as shown in said copending application, and a hand switch 65 is therefore interposed in the current supply line 66 which is included in circuits 61 and 61a in order to stop the automatic operation of the valves, and which switch may be opened to prevent energizing of the relay switches.

In order to automatically steer the machine as it advances, the following arrangement is provided:

A feeler unit Fl--identical with the feeler units F already described--is supported from a bracket 67 secured on, and projecting laterally from, a fender 15 on one side or the other of the machine and at the front of such fender (see Figs. 2 and 3). Said unit F1, however, is mounted so that the probe P thereof depends vertically and straddles the adjacent grade wire 32 from above.

By reason of this mounting of the probe, the probeactllated switches 48aV are alternately closed upon lateral vases-,45a

swinging of said probe to one side or the other, as the wire 32 deviatcs from a straight line. i

The motors 17 are connected to the generator 23 in parallel by separate circuits 68 and 68a; a hand switch 69 being interposed in the common line 70 of'such circuits. Interposed in circuits 68 and 68a are normally closed relay -switches 71 and 71a respectively; the actuating coils 72 of such relays being connected to the switches 48a by circuit wires 73.

Since the switches 71 and 71a are normally closed, the motors 17 are normally energized, and thus drive the track units to advance the machine; said motors having the same speed and power so that the machine will travel a path or course designated by the grade wire 32.

The actuating circuits for the relay switches 71 and 71a are arranged relative to the feeler actuated switches 48a so that when the adjacent grade wire deviatcs to the right, for instance, and the upper portion of the probe P swings to the left, the relay coil 72 of the right-hand motor control circuit 68a will be actuated to open switch 71a.

The right hand motor 17 will thus be deenergized, and the left hand motor will continue to operate so as to cause the machine to be turned to the right.

In case it is desired that the automatic steering unit shall not function, a hand switch 74 is interposed in the current feed line 75 of circuits 73.

The swingable feeler or probe units mounted on the screw shafts 36 being adjustable vertically as well as laterally relative to the supporting brackets, the probes are readily adjusted to the wires 32 regardless of the height of said wires from the ground, or the lateral spacing of such wires from the machine, within reasonable limits. Should further adjustment of the feeler units F be necessary, the arms 33 may be raised or lowered relative to the bolsters.

Also, when it is desired to place one track unit at a higher or lower level than the other, as when one track is to rest on a paving strip already laid while additional paving is to be poured onto the ground along-side said laid strip, one bolster or the other may be adjusted relative to the uprights 28 by bolting the bolster plates 26 in a different position on the upright plates 27. By so doing, the relative difference in level of the track units 1 is obtained, while maintaining each bolster and track unit in 'their normal relationship to each other.

The track and bolster units being detachable from the paving machine itself, and the motors and generator unit being mounted on such bolster units, the latter may be detached for shipment, repair, or replacement without alecting the paving machine itself.

From the foregoing description it will be readily seen that there has been produced such a device as will substantially fuliill the objects of the invention, as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice such deviations from such detail may be resorted to as do not form a departure from the spirit of the invention, as defined by the appended claims.

Having thus described the invention the following is claimed as new and useful, and upon which Letters Patent are desired:

l. Supporting and level-control mechanism for a concrete-slab laying machine which includes a frame having longitudinally spaced uprights at the sides of the machine, self-propelled endless track units disposed laterally out from the uprights, bolsters above the track units, longitudinally spaced vertical hydraulical rams connecting each bolster and the corresponding track unit, level controlled means to actuate the rams, and means vertically adjustably connecting each bolster to the adjacent uprights.

2. Supporting and level-control mechanism for a concrete slab laying machine which includes a frame having 6 longitudinally spaced uprights at 'the sides k'ofi-the, machine, self-propelled endless track units disposed laterally out from the uprights, bolsters above thetrack units, longitudinally spaced vertical hydraulic rams connecting each bolster and the corresponding track'unit, and means .vertically adjustably connecting each bolsterzto the adjacent uprights; said means vcomprising vertical'plates on theuprights in facing relation to the bolsters, plates on the bolsters abutted against the rst named plates, and bolts detachably connecting corresponding pairs of abutting plates; the first named plates being relatively elongated and provided with rows of holes for selective engagement with the bolts when the abuting plates are shifted vertically relative to each other.

3. Supporting and level-control mechanism for a concrete-slab laying machine which includes la frame, selfpropelled endless track units at the sides of the frame, bolsters above said units and rigidly secured to the frame, a vertical hydraulic ram including a cylinder rigid with each bolster at one end thereof, another vertical hydraulic ram including a cylinder disposed at the other end of each bolster and mounted thereon for swivel movement about a transverse axis, the rams including depending plungers, each track unit including a longitudinal frame, and means including a transverse pivot connecting each plunger with the corresponding longitudinal frame.

4. In a concrete-slab laying machine, rigid bolsters secured to the machine on opposite `sides thereof, endless ground engaging track units under the bolsters, vertically adjustable means connecting each bolster and the adjacent track unit, means to actuate said adjustable means, a grade wire laterally oifset from such track unit and fixed at a level below that of the bolster, a feeler unit mounted on the machine to control the functioningof said actuating means and including a wire engaging element and a supporting bracket, and a rigid arm depending from said bolster in a position between and clear of the rade wire and the adjacent track unit and on which the bracket is secured.

5. A structure, as in claim 4, with means mounting the arm on the bolster for vertical adjustment relative thereto.

6. Supporting and level-control mechanism for a concrete-slab laying machine which includes a frame, selfpropelled endless track units at the sides of the frame, bolsters above said units and rigidly secured to the frame, a vertical hydraulic ram including a cylinder rigid with each bolster at one end thereof, another vertical hydraulic ram including a cylinder disposed at the other end of each bolster, the rams each including a depending plunger and each track unit including a longitudinal frame, means including a transverse pivot connecting each plunger with the corresponding last named frame, trunnions projecting laterally out from said other rams and turnably mounted in the adjacent bolster, and means mounting the trunnions in connection with the cylinders of said other rams for limited downward movement of the latter and the track units relative to the bolsters from a predetermined normal level.

7. Supporting and level-control mechanism for a concrete-slab laying machine which includes a frame, selfpropelled endless track units at the sides of the frame, bolsters above said units and rigidly secured to the frame, a vertical hydraulic ram including a cylinder rigid with each bolster at one end thereof, another vertical hydraulic ram including a cylinder disposed at the other end of each bolster, the rams each including a depending plunger and each track unit including a longitudinal frame, means including a transverse pivot connecting each plunger with the corresponding last named frame, trunnions projecting laterally out from 'said other rams and turnably mounted in the adjacent bolster, a ring slidable on the cylinder of each of said otherl rams and on which ring the trunnions are iixed, and a rigid stop shouldcr onsaid cylinder below and normally engaged by thc ring.

References `Cited in the le of this patent UNITED STATES PATENTS 8 Smith Dec. 7, 1926 Schmid June 14, 1932 Kakaska June 20, 1933 Blanchett Dec. 14, 1937 Webster Sept. 25, 1945 Shoiket et al. July 13, 1954 Poche Nov. 2. 1954 Crites Oct. 9, 1956 

